Multi-Stage Process and Device for Treatment Heavy Marine Fuel Oil and Resultant Composition including Microwave Promoted Desulfurization

ABSTRACT

A multi-stage process for reducing the environmental contaminants in an ISO 8217 compliant Feedstock Heavy Marine Fuel Oil involving a core desulfurizing process and a microwave treatment process as either a pre-treating step or post-treating step to the core process. The Product Heavy Marine Fuel Oil complies with ISO 8217 for residual marine fuel oils and has a sulfur level has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % to 1.0 mass. A process plant for conducting the process is also disclosed.

BACKGROUND

There are two basic marine fuel types, distillate based marine fuel, and residual based marine fuel. Distillate based marine fuel, also known as Marine Gas Oil (MGO) or Marine Diesel Oil (MDO) comprises petroleum fractions separated from crude oil in a refinery via a distillation process. Gasoil (also known as medium diesel) is a petroleum distillate intermediate in boiling range and viscosity between kerosene and lubricating oil containing a mixture of C₁₀ through C₁₉ hydrocarbons. Gasoil is used to heat homes and is used for heavy equipment such as cranes, bulldozers, generators, bobcats, tractors and combine harvesters. Generally maximizing gasoil recovery from residues is the most economic use because a refinery can crack gas oils into valuable gasoline and distillates. Diesel oils are similar to gas oils with diesel containing a mixture of C₁₀ through C₁₉ hydrocarbons, which include approximately 60% or more aliphatic hydrocarbons, 1-2% olefinic hydrocarbons, and 35% or less aromatic hydrocarbons. Marine Diesels may contain no over 15% residual process streams, and optionally no over 5% volume of polycyclic aromatic hydrocarbons (asphaltenes). Diesel fuels are primarily utilized as a land transport fuel and as blending component with kerosene to form aviation jet fuel.

Residual based fuels or Heavy Marine Fuel Oil (HMFO) comprises a mixture of process residues—the fractions that don't boil or vaporize even under vacuum conditions, and have an asphaltenes content between 3 and 20 percent by weight. Asphaltenes are large and complex polycyclic hydrocarbons that contribute to the fuel density, SARA properties and lubricity properties of HMFO which are desirable. Asphaltenes, however, have a propensity to form complex and waxy precipitates, especially in the presence of aliphatic (paraffinic) hydrocarbons. Once asphaltenes have precipitated out, they are notoriously difficult to re-dissolve and are described as fuel tank sludge in the marine shipping industry and marine bunker fueling industry.

Large ocean-going ships have relied upon HMFO to power large two stroke diesel engines for over 50 years. HMFO is a blend of polycyclic aromatics and residual hydrocarbons generated in the crude oil refinery process. Typical streams included in the formulation of HMFO include, but are not limited to: atmospheric tower bottoms (i.e. atmospheric residues), vacuum tower bottoms (i.e. vacuum residues) visbreaker residue, FCC Light Cycle Oil (LCO), FCC Heavy Cycle Oil (HCO) also known as FCC bottoms, FCC Slurry Oil, heavy gas oils; delayed cracker oil (DCO), polycylic aromatic hydrocarbons, De-asphalted oil (DAO); reclaimed land transport motor oils; slop oils, and minor portions (less than 20% vol.) of cutter oil, kerosene or diesel to achieve a desired viscosity. HMFO has an aromatic content higher than the marine distillate fuels noted above. The HMFO composition is complex and varies with the source of crude oil processed by the refinery and the processes utilized within the refinery to extract the most value out of a barrel of crude oil. The mixture of components is generally characterized as being viscous, high in sulfur and metal content, and high in asphaltenes making HMFO the one product of the refining process that has a per barrel value less than the feedstock crude oil itself.

Industry statistics indicate that about 90% of the HMFO sold contains 3.5 weight % sulfur. With an estimated total worldwide consumption of HMFO of approximately 300 million tons per year, the annual production of sulfur dioxide by the shipping industry is estimated to be over 21 million tons per year. Emissions from HMFO burning in ships contribute significantly to both global air pollution and local air pollution levels.

MARPOL, the International Convention for the Prevention of Pollution from Ships, as administered by the International Maritime Organization (IMO) was enacted to prevent pollution from ships. In 1997, a new annex was added to MARPOL; the Regulations for the Prevention of Air Pollution from Ships—Annex VI to minimize airborne emissions from ships and their contribution to air pollution. A revised Annex VI with tightened emissions limits on sulfur oxides, nitrogen oxides, ozone depleting substances and volatile organic compounds (SOx, NOx, ODS, VOC) was adopted in October 2008 and effective 1 Jul. 2010 (hereafter called Annex VI (revised)).

MARPOL Annex VI (revised) established a set of stringent emissions limits for vessel operations in designated Emission Control Areas (ECAs). The ECAs under MARPOL Annex VI (revised) are: i) Baltic Sea area—as defined in Annex I of MARPOL-SOx only; ii) North Sea area—as defined in Annex V of MARPOL-SOx only; iii) North American—as defined in Appendix VII of Annex VI of MARPOL-SOx, NOx and PM; and, iv) United States Caribbean Sea area—as defined in Appendix VII of Annex VI of MARPOL-SOx, NOx and PM.

Annex VI (revised) was codified in the United States by the Act to Prevent Pollution from Ships (APPS). Under the authority of APPS, the U.S. Environmental Protection Agency (the EPA), in consultation with the United States Coast Guard (USCG), promulgated regulations which incorporate by reference the full text of MARPOL Annex VI (revised). See 40 C.F.R. § 1043.100(a)(1). On Aug. 1, 2012 the maximum sulfur content of all marine fuel oils used onboard ships operating in US waters/ECA cannot exceed 1.00% wt. (10,000 ppm) and on Jan. 1, 2015 the maximum sulfur content of all marine fuel oils used in the North American ECA was lowered to 0.10% wt. (1,000 ppm). At the time of implementation, the United States government indicated that vessel operators must vigorously prepare for the 0.10% wt. (1,000 ppm) US ECA marine fuel oil sulfur standard. To encourage compliance, the EPA and USCG refused to consider the cost of compliant low sulfur fuel oil to be a valid basis for claiming that compliant fuel oil was not available for purchase. For the past five years there has been a very strong economic incentive to meet the marine industry demands for low sulfur HMFO, however technically viable solutions have not been realized. There has been an on-going and urgent demand for processes and methods for making a low sulfur HMFO compliant with ECA MARPOL Annex VI emissions requirements.

Under the revised MARPOL Annex VI, a global sulfur cap for HMFO (the primary source for Sox emissions from ships) was set at 3.50% wt. effective 1 Jan. 2012; then further reduced to 0.50% wt, effective 1 Jan. 2020. Under the global limit, all ships must use HMFO with a sulfur content of not over 0.50% wt. This regulation has been the subject of much discussion in both the marine shipping and marine fuel bunkering industry. There has been a very strong economic incentive to meet the international marine industry demands for low sulfur HMFO that is ISO 8217 compliant, however technically viable solutions have not been realized. There is an on-going and urgent demand for processes and methods for making a low sulfur HMFO ISO 8217 compliant with the global MARPOL Annex VI emissions requirements.

Primary control solutions: A focus for compliance with the MARPOL requirements has been on primary control solutions for reducing the sulfur levels in marine fuel components prior to combustion based on the substitution of HMFO with alternative fuels. Because of the potential risks to ships propulsion systems (i.e. fuel systems, engines, etc.) when a ship switches fuel, the conversion process must be done safely and effectively to avoid any technical issues. However, each alternative fuel has both economic and technical difficulties adapting to the decades of shipping infrastructure and bunkering systems based upon HMFO utilized by the marine shipping industry.

Replacement of heavy fuel oil with marine gas oil or marine diesel: A third proposed primary solution is to simply replace HMFO with marine gas oil (MGO) or marine diesel (MDO). The first major difficulty is the constraint in global supply of distillate materials that make up over 90% vol of MGO and MDO. It is reported that the effective spare capacity to produce MGO is less than 100 million metric tons per year resulting in an annual shortfall in marine fuel of over 200 million metric tons per year. Refiners not only lack the capacity to increase the production of MGO, but they have no economic motivation because higher value and higher margins can be obtained from ultra-low sulfur diesel fuel for land-based transportation systems (i.e. trucks, trains, mass transit systems, heavy construction equipment, etc.). A distillate only solution also ignores the economic impacts of disposing of the refinery streams that previously went to the high sulfur HMFO blending pool.

Blending: Another primary solution is the blending of HMFO with lower sulfur containing fuels such as low sulfur marine diesel (0.1% wt. sulfur) to achieve a Product HMFO with a sulfur content of 0.5% wt. In a theoretical straight blending approach (based on linear blending) every 1 ton of HSFO (3.5% sulfur) requires 7.5 tons of MGO or MDO material with 0.1% wt. S to achieve a sulfur level of 0.5% wt. HMFO. One of skill in the art of fuel blending will immediately understand that blending large volumes of distillate into high sulfur HMFO hurts key properties of the HMFO, specifically lubricity, viscosity and density are substantially altered. Further a blending process may create a fuel that is unstable and incompatible with other blends of distillate and HMFO. A blended fuel is likely to result in the precipitation of asphaltenes and/or waxing out of highly paraffinic materials from the distillate material forming an intractable fuel tank sludge. Such a risk to the primary propulsion system is not acceptable for a cargo ship in the open ocean.

Processing of residual oils. For the past several decades, the focus of refining industry research efforts related to the processing of heavy oils (crude oils, distressed oils, or residual oils) has been on upgrading the properties of these low value refinery process oils to create lighter oils with greater value. The challenge has been that crude oil, distressed oil and residues can be unstable and contain high levels of sulfur, nitrogen, phosphorous, metals (especially vanadium and nickel) and asphaltenes. Much of the nickel and vanadium is in difficult to remove chelates with porphyrins. Vanadium and nickel porphyrins and other metal organic compounds are responsible for catalyst contamination and corrosion problems in the refinery. The sulfur, nitrogen, and phosphorous, are removed because they are well-known poisons for the precious metal (platinum and palladium) catalysts utilized in the processes downstream of the atmospheric or vacuum distillation towers.

The difficulties treating atmospheric or vacuum residual streams has been known for many years and has been the subject of considerable research and investigation. Numerous residue-oil conversion processes have been developed in which the goals are same, 1) create a more valuable, preferably distillate range hydrocarbon product; and 2) concentrate the contaminates such as sulfur, nitrogen, phosphorous, metals and asphaltenes into a form (coke, heavy coker residue, FCC slurry oil) for removal from the refinery stream. Well known and accepted practice in the refining industry is to increase the reaction severity (elevated temperature and pressure) to produce hydrocarbon products that are lighter and more purified, increase catalyst life times and remove sulfur, nitrogen, phosphorous, metals and asphaltenes from the refinery stream.

In summary, since the announcement of the MARPOL standards reducing the global levels of sulfur in HMFO, refiners of crude oil have been unsuccessful in their technical efforts to create a process for the production of a low sulfur substitute for HMFO. Despite the strong governmental and economic incentives and needs of the international marine shipping industry, refiners have little economic reason to address the removal of environmental contaminates from HMFOs. The global refining industry has been focused upon generating greater value from each barrel of oil by creating light hydrocarbons (i.e. diesel and gasoline) and concentrating the environmental contaminates into increasingly lower value streams (i.e. residues) and products (petroleum coke, HMFO). Shipping companies have focused on short term solutions, such as the installation of scrubbing units, or adopting the limited use of more expensive low sulfur marine diesel and marine gas oils as a substitute for HMFO. On the open seas, most if not all major shipping companies continue to utilize the most economically viable fuel, that is HMFO. There remains a long standing and unmet need for processes and devices that remove the environmental contaminants (i.e. sulfur, nitrogen, phosphorous, metals especially vanadium and nickel) from HMFO without altering the qualities and properties that make HMFO the most economic and practical means of powering ocean going vessels.

SUMMARY

It is a general objective to reduce the environmental contaminates from a Heavy Marine Fuel Oil (HMFO) in a multi stage process that minimizes the changes in the desirable properties of the HMFO and minimizes the unnecessary production of by-product hydrocarbons (i.e. light hydrocarbons having C₁-C₄ and wild naphtha (C₄-C₂₀)).

A first aspect and illustrative embodiment encompasses a multi-stage process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process involving: contacting a Feedstock Heavy Marine Fuel Oil with a microwave treatment process to give a pre-treated Feedstock Heavy Marine Fuel Oil; mixing a quantity of the pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under desulfurizing conditions to form a Process Mixture from the Feedstock Mixture; receiving the Process Mixture and separating the Product Heavy Marine Fuel Oil liquid components of the Process Mixture from the gaseous components and by-product hydrocarbon components of the Process Mixture and, discharging the Product Heavy Marine Fuel Oil.

A second aspect and illustrative embodiment encompasses a process for reducing the environmental contaminants in HMFO, in which the process involves: mixing a quantity of Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under desulfurizing conditions to form a Process Mixture from the Feedstock Mixture; receiving the Process Mixture and separating the liquid components of the Process Mixture from the bulk gaseous components of the Process Mixture; receiving the liquid components and contacting the liquid components with a microwave treatment process; then separating any residual gaseous components and by-product hydrocarbon components from the Product Heavy Marine Fuel Oil; and, discharging the Product Heavy Marine Fuel Oil.

A third and fourth aspect and illustrative embodiment encompasses a device for reducing environmental contaminants in a Feedstock HMFO and producing a Product HMFO. The illustrative devices embody the above illustrative processes on a commercial scale.

A fifth aspect and illustrative embodiment encompasses a Heavy Marine Fuel Oil composition resulting from the above illustrative processes.

DESCRIPTION OF DRAWINGS

FIG. 1 is a process block flow diagram of an illustrative core process to produce Product HMFO.

FIG. 2 is a process flow diagram of a multistage process utilizing a microwave treatment process to pre-treat the feedstock HMFO and a subsequent core process to produce Product HMFO.

FIG. 3 is a process flow diagram of a multi-stage process utilizing a core process followed by a subsequent microwave treatment process to produce Product HMFO.

FIG. 4 is a basic schematic diagram of a plant to produce Product HMFO utilizing a combination of a microwave treatment process to pre-treat the feedstock HMFO and a subsequent core process to produce Product HMFO.

FIG. 5 is a basic schematic diagram of a plant to produce Product HMFO utilizing a combination of a core process and microwave treatment process to produce Product HMFO.

DETAILED DESCRIPTION:

The inventive concepts as described herein utilize terms that should be well known to one of skill in the art, however certain terms are utilized having a specific intended meaning and these terms are defined below:

Heavy Marine Fuel Oil (HMFO) is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels except for the concentration levels of the Environmental Contaminates.

Environmental Contaminates are organic and inorganic components of HMFO that result in the formation of SO_(x), NO_(x) and particulate materials upon combustion.

Feedstock HMFO is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels except for the concentration of Environmental Contaminates, preferably the Feedstock HMFO has a sulfur content greater than the global MARPOL standard of 0.5% wt. sulfur, and preferably and has a sulfur content (ISO 14596 or ISO 8754) between the range of 5.0% wt. to 1.0% wt.

Product HMFO is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels and achieves a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754), and preferably a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 1.0% wt.

Activating Gas: is a mixture of gases utilized in the process combined with the catalyst to remove the environmental contaminates from the Feedstock HMFO.

Fluid communication: is the capability to transfer fluids (either liquid, gas or combinations thereof, which might have suspended solids) from a first vessel or location to a second vessel or location, this may encompass connections made by pipes (also called a line), spools, valves, intermediate holding tanks or surge tanks (also called a drum).

Merchantable quality: is a level of quality for a residual marine fuel oil so the fuel is fit for the ordinary purpose it should serve (i.e. serve as a residual fuel source for a marine ship) and can be commercially sold as and is fungible with heavy or residual marine bunker fuel.

Bbl or bbl: is a standard volumetric measure for oil; 1 bbl =0.1589873 m³ ; or 1 bbl=158.9873 liters; or 1 bbl=42.00 US liquid gallons.

Bpd: is an abbreviation for Bbl per day.

SCF: is an abbreviation for standard cubic foot of a gas; a standard cubic foot (at 14.73 psi and 60° F.) equals 0.0283058557 standard cubic meters (at 101.325 kPa and 15° C.).

The inventive concepts are illustrated in more detail in this description referring to the drawings, in which FIG. 1 shows the generalized block process flows for a core process of reducing the environmental contaminates in a Feedstock HMFO and producing a Product HMFO. A predetermined volume of Feedstock HMFO (2) is mixed with a predetermined quantity of Activating Gas (4) to give a Feedstock Mixture. The Feedstock HMFO utilized generally complies with the bulk physical and certain key chemical properties for a residual marine fuel oil otherwise compliant with ISO 8217 (2017) exclusive of the Environmental Contaminates. More particularly, when the Environmental Contaminate is sulfur, the concentration of sulfur in the Feedstock HMFO may be between the range of 5.0% wt. to 1.0% wt. The Feedstock HMFO should have bulk physical properties required of an ISO 8217 (2017) compliant HMFO of: a maximum kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass % and preferably also a maximum aluminum plus silicon (ISO 10478) content of 60 mg/kg. Environmental Contaminates other than sulfur that may be present in the Feedstock HMFO over the ISO requirements may include vanadium, nickel, iron, aluminum and silicon substantially reduced by the process of the present invention. However, one of skill in the art will appreciate that the vanadium content serves as a general indicator of these other Environmental Contaminates. In one preferred embodiment the vanadium content is ISO compliant so the Feedstock MHFO has a maximum vanadium content (ISO 14597) between the range from 350 mg/kg to 450 ppm mg/kg.

As for the properties of the Activating Gas, the Activating Gas should be selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane. The mixture of gases within the Activating Gas should have an ideal gas partial pressure of hydrogen (p_(H2)) greater than 90% of the total pressure of the Activating Gas mixture (P) and more preferably wherein the Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 95% of the total pressure of the Activating Gas mixture (P). It will be appreciated by one of skill in the art that the molar content of the Activating Gas is another criteria the Activating Gas should have a hydrogen mole fraction in the range between 80% and 100% of the total moles of Activating Gas mixture.

The Feedstock Mixture (i.e. mixture of Feedstock HMFO and Activating Gas) is brought up to the process conditions of temperature and pressure and introduced into a first vessel, preferably a reactor vessel, so the Feedstock Mixture is then contacted with one or more catalysts (8) to form a Process Mixture from the Feedstock Mixture.

The core process conditions are selected so the ratio of the quantity of the Activating Gas to the quantity of Feedstock HMFO is 250 scf gas/bbl of Feedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO; and preferably between 2000 scf gas/bbl of Feedstock HMFO 1 to 5000 scf gas/bbl of Feedstock HMFO more preferably between 2500 scf gas/bbl of Feedstock HMFO to 4500 scf gas/bbl of Feedstock HMFO. The process conditions are selected so the total pressure in the first vessel is between of 250 psig and 3000 psig; preferably between 1000 psig and 2500 psig, and more preferably between 1500 psig and 2200 psig. The process conditions are selected so the indicated temperature within the first vessel is between of 500° F. to 900° F., preferably between 650° F. and 850° F. and more preferably between 680° F. and 800° F. The process conditions are selected so the liquid hourly space velocity within the first vessel is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst; preferably between 0.08 oil/hour/m³ catalyst and 0.5 oil/hour/m³ catalyst; and more preferably between 0.1 oil/hour/m³ catalyst and 0.3 oil/hour/m³ catalyst to achieve deep desulfurization with product sulfur levels below 0.1 ppmw.

One of skill in the art will appreciate that the core process conditions are determined to consider the hydraulic capacity of the unit. Exemplary hydraulic capacity for the treatment unit may be between 100 bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day, preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl of Feedstock HMFO/day, more preferably between 5,000 bbl of Feedstock HMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferably between 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of Feedstock HMFO/day.

The core process may utilize one or more catalyst systems selected from the group consisting of: an ebulliated bed supported transition metal heterogeneous catalyst, a fixed bed supported transition metal heterogeneous catalyst, and a combination of ebulliated bed supported transition metal heterogeneous catalysts and fixed bed supported transition metal heterogeneous catalysts. One of skill in the art will appreciate that a fixed bed supported transition metal heterogeneous catalyst will be the technically easiest to implement and is preferred. The transition metal heterogeneous catalyst comprises a porous inorganic oxide catalyst carrier and a transition metal catalyst. The porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier. The transition metal component of the catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table. In a preferred and illustrative embodiment, the transition metal heterogeneous catalyst is a porous inorganic oxide catalyst carrier and a transition metal catalyst, in which the preferred porous inorganic oxide catalyst carrier is alumina and the preferred transition metal catalyst is Ni—Mo, Co—Mo, Ni—W or Ni—Co—Mo.

The Process Mixture (10) in this core process is removed from the first vessel (8) and from being in contact with the one or more catalyst and is sent via fluid communication to a second vessel (12), preferably a gas-liquid separator or hot separators and cold separators, for separating the liquid components (14) of the Process Mixture from the bulk gaseous components (16) of the Process Mixture. The gaseous components (16) are treated beyond the battery limits of the immediate process. Such gaseous components may include a mixture of Activating Gas components and lighter hydrocarbons (mostly methane, ethane and propane but some wild naphtha) that may have been formed as part of the by-product hydrocarbons from the process.

The Liquid Components (16) in this core process are sent via fluid communication to a third vessel (18), preferably a fuel oil product stripper system, for separating any residual gaseous components (20) and by-product hydrocarbon components (22) from the Product HMFO (24). The residual gaseous components (20) may be a mixture of gases selected from the group consisting of: nitrogen, hydrogen, carbon dioxide, hydrogen sulfide, gaseous water, C₁-C₅ hydrocarbons. This residual gas is treated outside of the battery limits of the immediate process, combined with other gaseous components (16) removed from the Process Mixture (10) in the second vessel (12). The liquid by-product hydrocarbon component, which are condensable hydrocarbons formed in the process (22) may be a mixture selected from the group consisting of C₅-C₂₀ hydrocarbons (wild naphtha) (naphtha—diesel) and other condensable light hydrocarbons C₃-C₈ that can be utilized as part of the motor fuel blending pool or sold as gasoline and diesel blending components on the open market. These liquid by-product hydrocarbons should be less than 15% wt., preferably less than 5% wt. and more preferably less than 3% wt. of the overall process mass balance.

The Product HMFO (24) resulting from the core process is discharged via fluid communication into storage tanks beyond the battery limits of the immediate process. The Product HMFO complies with ISO 8217 (2017) and has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % to 1.0 mass % preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % ppm and 0.7 mass % and more preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.1 mass % and 0.5 mass %. The vanadium content of the Product HMFO is also ISO compliant with a maximum vanadium content (ISO 14597) between the range from 350 mg/kg to 450 ppm mg/kg, preferably a vanadium content (ISO 14597) between the range of 200 mg/kg and 300 mg/kg and more preferably a vanadium content (ISO 14597) less than 50 mg/kg.

The Product HFMO should have bulk physical properties of: a maximum of kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum of density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass % and also preferably a aluminum plus silicon (ISO 10478) content of less than 60 mg/kg.

The Product HMFO will have a sulfur content (ISO 14596 or ISO 8754) between 1% and 20% of the maximum sulfur content of the Feedstock Heavy Marine Fuel Oil. That is the sulfur content of the Product will be reduced by about 80% or greater when compared to the Feedstock HMFO. Similarly, the vanadium content (ISO 14597) of the Product Heavy Marine Fuel Oil is between 1% and 20% of the maximum vanadium content of the Feedstock Heavy Marine Fuel Oil. One of skill in the art will appreciate that the above data indicates a substantial reduction in sulfur and vanadium content indicate a process having achieved a substantial reduction in the Environmental Contaminates from the Feedstock HMFO while maintaining the desirable properties of an ISO compliant HMFO.

As a side note, the residual gaseous component is a mixture of gases selected from the group consisting of: nitrogen, hydrogen, carbon dioxide, hydrogen sulfide, gaseous water, C1-C5 hydrocarbons. An amine scrubber will effectively remove the hydrogen sulfide content which can then be processed using technologies and processes well known to one of skill in the art. In one preferable illustrative embodiment, the hydrogen sulfide is converted into elemental sulfur using the well-known Claus process. An alternative embodiment utilizes a proprietary process for conversion of the Hydrogen sulfide to hydrosulfuric acid. The sulfur is removed from entering the environment prior to combusting the HMFO in a ships engine. The cleaned gas can be vented, flared or more preferably recycled back for use as Activating Gas.

Microwave Treatment Process: It will be appreciated by one of skill in the art, that the conditions utilized in the core process have been intentionally selected to minimize cracking of hydrocarbons, but remove significant levels of sulfur from the Feedstock HMFO. However, one of skill in the art will also appreciate there may be certain compounds present in the Feedstock HMFO removal of which would have a positive impact upon the desirable bulk properties of the Product HMFO. These processes and systems must achieve this without substantially altering the desirable bulk properties (i.e. compliance with ISO 8217 (2017) exclusive of sulfur content) of the Product HMFO. Irradiation of materials using microwaves (MW) is used in several industrial applications. Various articles and patents claim successful use of microwave technologies (MW) applied to the processing of petroleum and to accelerate chemical processes which require heating. U.S. Pat. No. 6,106,675; and US. Patent Application US2011/0155558 specify various methods of treating petroleum hydrocarbons with microwaves. U.S. Pat. No. 8,403,043 and U.S. Pat. No. 8,807,214 disclose a process utilizing microwaves in the presence of catalyst and hydrogen to desulfurize crude oils.

Microwaves (MW) are non-ionizing electromagnetic radiations with a wavelength of 1 meter (m) to 1 millimeter (mm) corresponding to a frequency interval of 300 MHz to 300 GHz. In the heating mechanism using MW, the electromagnetic energy absorbed by the material is transformed into thermal energy. The frequencies of 915 MHz, 2450 MHz, 5800 MHz and 22125 MHz were defined in an international agreement for equipment for medical, scientific, industrial and domestic applications, including in this the domestic microwave.

Frequencies of 915 MHz and 2450 MHz are the most employed in industrial applications. In domestic ovens the frequency of 2450 MHz is generally used, with a wavelength of 12 cm and a power of the order of 1000 W. There are various forms of microwave generators, continuous and pulsed, and models with the power of tens of kW up to a MW. Radiation within the range of microwaves for industrial applications may be generated by a range of devices, such as: magnetrons, power grid tubes, klystrons, klystrodes, cross-field amplifiers, traveling wave tubes (TWT) and gyrotrons. These devices are built according to the size of the application, to operate in a wide range of radiation powers and frequencies.

Dielectric materials with a high loss factor interact with microwaves and convert the electromagnetic energy into thermal energy, heating up with the absorption and concomitant attenuation of the microwaves as these propagate in their interior. This process is dielectric heating and may act differently on loads of hydrocarbons, reagents and catalysts, even when in direct contact between these and homogenously mixed, different to heating via conduction or convection.

Some have noted that hydroprocessing catalysts recently removed from units or stored free of contact with the atmosphere interact more effectively with microwaves. It is believed these catalysts have a synergic effect between their catalytically active sites and their capacity to absorb microwaves. This synergy, associated with a local temperature higher than the average temperature of the reaction medium, creates a nanoreactor in which the reactions observed occur. Reactions occur in the active sites of the catalyst in contact with the hydrocarbon, subject to the synergy of the irradiation of electromagnetic waves. The energy applied to the reaction system via microwave irradiation is solely that necessary to the heating of the nanoreactors, the area of the active microwave absorbent sites, around which the reactions the object of this process occur.

The present process involves the treatment of HMFO in the presence of microwave absorbent materials, more preferentially those which absorb radiation in localized sites forming nanoreactors. This process, which may operate in a batch or continuous regimen, in a fixed, fluidized or slurry bed occurs in the presence of microwave absorbent materials such as catalysts, spent refinery catalysts, preferentially those materials which absorb radiation in localized sites such as hydro refining catalysts such as those of the alumina supported NiMo or CoMo type, even those which have been used in hydrotreatment units (HDT) at petroleum refineries. Other catalysts, both new and used, which also have microwave absorbent areas or sites, may be used in this invention, with an active phase composed of transition or lanthanide metals as oxides or sulfides.

By way of the appropriate choice of catalysts, whose active sites also behave as selective microwave absorbers, additional gains may be obtained, such as the reduced viscosity of the treated loads and reduced of contaminants such as nitrogen and sulfur present in these heavy oils.

The Microwave Treatment Unit (MTU) comprises a conventional reactor attached via wave windows and guides to a microwave source. Construction of this unit, which may operate at relatively low pressures lower than 2 MPa, and temperatures equal to or lower than 300° C., adopted in this process would not present technical difficulties for an experienced technician in this field. For example see the reactors disclosed in EP1985359 or U.S. Pat. No. 9,302,245 as an illustrative examples of microwave energy based reactors that allow for elevated temperature, pressure, presence of catalytic materials, and continuous flow of feedstock materials (i.e. Feedstock HMFO and optionally hydrogen).

Generally, the microwave treatment process contemplated within the scope of the present invention involves placing the referred Feedstock HMFO or Product HMFO into contact in batches or continually with a fixed or slurry bed subject to the action of microwave energy of a wavelength of a range of 1 m to 1 mm, corresponding to a frequency interval of 300 MHz to 300 GHz. The bed comprises a microwave absorbent material, such as a spent catalyst from a hydrotreatment unit. The load input temperature ranges between 25° C. and 300° C., preferably at a temperature ranging between 30° C. and 260° C. The pressure of the system is not critical and may be adjusted in such a way that prior to treatment it is equal to or lower than the pressure of the previous unit and after treatment the current is at the normal pressure of this system. Spatial velocity ranges from between 0.10 h⁻¹and 10 h⁻¹, preferably within a range of between 0.2 h⁻¹ and 6 h⁻¹. The microwave radiation is normally conducted to the reactor guided in wave guide ducts connected to the reactor via windows. These windows must be appropriate for the radiation to pass through but must also withstand the pressure conditions which vary from atmospheric to 50 bar and temperatures of the reaction medium which range from 25° C. to 300° C., characteristic of the process. Construction of microwave transparent windows capable of withstanding the pressures and temperatures for the process is within the skill of those experienced in the field.

The microwave absorbent material used in this invention may be, for example, selected from the group of metallic oxides, sulfates, coking fines tailings; compounds containing nanostructured materials such as nanofibers and nanotubes; catalysts or mixtures of catalysts disposed of at fluid catalytic cracking units; catalysts or mixtures of catalysts disposed of at hydrotreatment units, comprised of transition metals (such as Co, Mo, Ni, etc.), supported on refractory oxides which may be chosen from among alumina, silica, titanium, zirconium and/or mixtures, and others, in which the material which supported the active phase of the absorbent material may be preferably transparent to microwaves. With spent catalysts, these may have suffered a phase of intermediary rectification or not in the presence of an inert gas. It may be necessary to include paramagnetic materials within the catalyst, such as iron oxides or iron sulfides, to promote the transfer of microwave energy to the hydrocarbons and hydrogen gas present in the surroundings.

An advantage of this process is that it operates at relatively low temperature and pressure. The operating phase of the process enables it to be scaled up without the characteristics difficulties of hooking up a microwave source to industrial processes which used high pressure and temperature.

In this description, items already described above as part of the core process have retained the same numbering and designation for ease of description. As show in FIG. 2, a MTU 3 can be utilized to pre-treat the Feedstock HMFO prior to mixing with the Activating Gas 4 as part of the core process disclosed above. While simplistically represented in this drawing, the MTU 3 may be multiple parallel or in series MTU's however the MTU may be as simple as a single reactor vessel in which the HMFO is exposed to microwave energy in the presence of catalyst. While a single a fixed bed, flow through/contact vessel may be used, it may be advantageous and it is preferable to have multiple contact vessels in parallel with each other to allow for one unit to be active while a second or third unit are being reloaded. Such an arrangement involving multiple parallel contact vessels with pipes/switching valves, etc . . . is well within the abilities of one of skill in the art of refinery process design and operation.

An alternative illustrative embodiment is shown in FIG. 3 in which an MTU 17 is utilized after the core sulfur removal process step, but prior to the separation of the Product HMFO 24 from any Residual Gas 20 and By-Product 22 (i.e. mostly C₁-C₄ hydrocarbons, and wild naptha). In such a configuration the MTU effectively acts as a polishing unit to remove TAN and viscosity inducing complex molecules present in the HMFO not removed under the conditions in the core process step. As with the pre-treatment MTU described above, the conditions in this post-treatment MTU are moderate. It is believed that because this step of the process will be conducted under very modest conditions (i.e. moderately elevated temperatures sufficient to make the HMFO liquid-like in this process) that will have minimal to no adverse impact upon the bulk physical properties of the product HMFO. In this way one may achieve a level of total acidity and viscosity reduction for a HMFO not achieved otherwise while minimizing the cracking of hydrocarbons and maintaining the other desirable bulk properties of the HMFO.

Product HMFO The Product HFMO resulting from the disclosed illustrative process is of merchantable quality for sale and use as a heavy marine fuel oil (also known as a residual marine fuel oil or heavy bunker fuel) and exhibits the bulk physical properties required for the Product HMFO to be an ISO compliant (i.e. ISO 8217 (2017)) residual marine fuel oil. The Product HMFO should exhibit the bulk properties of: a maximum kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass % and preferably a maximum aluminum plus silicon (ISO 10478) content of 60 mg/kg.

The Product HMFO has a sulfur content (ISO 14596 or ISO 8754) less than 0.5 wt % and preferably less than 0.1% wt. and complies with the IMO Annex VI requirements for a low sulfur and preferably an ultra-low sulfur HMFO. That is the sulfur content of the Product HMFO has been reduced by about 90% or greater when compared to the Feedstock HMFO. Similarly, the vanadium content (ISO 14597) of the Product Heavy Marine Fuel Oil is less than 10% and more preferably less than 1% of the maximum vanadium content of the Feedstock Heavy Marine Fuel Oil. One of skill in the art will appreciate that a substantial reduction in sulfur and vanadium content of the Feedstock HMFO indicates a process having achieved a substantial reduction in the Environmental Contaminates from the Feedstock HMFO; of equal importance is this has been achieved while maintaining the desirable properties of an ISO 8217 (2017) compliant HMFO.

The Product HMFO not only complies with ISO 8217 (2017) (and is merchantable as a residual marine fuel oil or bunker fuel), the Product HMFO has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 1.0% wt. preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. ppm and 0.5% wt. and more preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.1% wt. and 0.5% wt. The vanadium content of the Product HMFO is well within the maximum vanadium content (ISO 14597) required for an ISO 8217 (2017) residual marine fuel oil exhibiting a vanadium content lower than 450 ppm mg/kg, preferably a vanadium content (ISO 14597) lower than 300 mg/kg and more preferably a vanadium content (ISO 14597) less than 50 mg/kg.

One knowledgeable in the art of marine fuel blending, bunker fuel formulations and the fuel logistical requirements for marine shipping fuels will readily appreciate that without further compositional changes or blending, the Product HMFO can be sold and used as a low sulfur MARPOL Annex VI compliant heavy (residual) marine fuel oil that is a direct substitute for the high sulfur heavy (residual) marine fuel oil or heavy bunker fuel currently in use. One illustrative embodiment is an ISO 8217 (2017) compliant low sulfur heavy marine fuel oil comprising (and preferably consisting essentially of) a hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil, wherein the sulfur levels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil is greater than 0.5% wt. and wherein the sulfur levels of the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil is less than 0.5% wt. Another illustrative embodiment is an ISO 8217 (2017) compliant ultra-low sulfur heavy marine fuel oil comprising (and preferably consisting essentially of) a 100% hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil, wherein the sulfur levels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil is greater than 0.5% wt. and wherein the sulfur levels of the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil is less than 0.1% wt.

Because of the present invention, multiple economic and logistical benefits to the bunkering and marine shipping industries can be realized. The benefits include minimal changes to the existing heavy marine fuel bunkering infrastructure (storage and transferring systems); minimal changes to shipboard systems are needed to comply with emissions requirements of MARPOL Annex VI (revised); no additional training or certifications for crew members will be needed, amongst the realizable benefits. Refiners will also realize multiple economic and logistical benefits, including: no need to alter or rebalance the refinery operations and product streams to meet a new market demand for low sulfur or ultralow sulfur HMFO; no additional units are needed in the refinery with additional hydrogen or sulfur capacity because the illustrative process can be conducted as a stand-alone unit; refinery operations can remain focused on those products that create the greatest value from the crude oil received (i.e. production of petrochemicals, gasoline and distillate (diesel); refiners can continue using the existing slates of crude oils without having to switch to sweeter or lighter crudes to meet the environmental requirements for HMFO products.

Heavy Marine Fuel Composition One aspect of the present inventive concept is a fuel composition comprising, but preferably consisting essentially of, the Product HMFO resulting from the processes disclosed, and may optionally include Diluent Materials. The bulk properties of the Product HMFO itself complies with ISO 8217 (2017) and meets the global IMO Annex VI requirements for maximum sulfur content (ISO 14596 or ISO 8754). If ultra-low levels of sulfur are desired, the process of the present invention achieves this and one of skill in the art of marine fuel blending will appreciate that a low sulfur or ultra-low sulfur Product HMFO can be utilized as a primary blending stock to form a global IMO Annex VI compliant low sulfur Heavy Marine Fuel Composition. Such a low sulfur Heavy Marine Fuel Composition will comprise (and preferably consist essentially of): a) the Product HMFO and b) Diluent Materials. In one embodiment, the majority of the volume of the Heavy Marine Fuel Composition is the Product HMFO with the balance of materials being Diluent Materials. Preferably, the Heavy Marine Fuel Composition is at least 75% by volume, preferably at least 80% by volume, more preferably at least 90% by volume, and furthermore preferably at least 95% by volume Product HMFO with the balance being Diluent Materials.

Diluent Materials may be hydrocarbon or non-hydrocarbon based materials mixed into or combined with or added to, or solid particle materials suspended in, the Product HMFO. The Diluent Materials may intentionally or unintentionally alter the composition of the Product HMFO but not so the resulting mixture violates the ISO 8217 (2017) standards for the properties of residual marine fuels or fails to have a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754). Examples of Diluent Materials considered hydrocarbon based materials include: Feedstock HMFO (i.e. high sulfur HMFO); distillate based fuels such as road diesel, gas oil, MGO or MDO; cutter oil (which is used in formulating residual marine fuel oils); renewable oils and fuels such as biodiesel, methanol, ethanol ; synthetic hydrocarbons and oils based on gas to liquids technology such as Fischer-Tropsch derived oils, synthetic oils such as those based on polyethylene, polypropylene, dimer, trimer and poly butylene; refinery residues or other hydrocarbon oils such as atmospheric residue, vacuum residue, fluid catalytic cracker (FCC) slurry oil, FCC cycle oil, pyrolysis gasoil, cracked light gas oil (CLGO), cracked heavy gas oil (CHGO), light cycle oil (LCO), heavy cycle oil (HCO), thermally cracked residue, coker heavy distillate, bitumen, de-asphalted heavy oil, visbreaker residue, slop oils, asphaltinic oils; used or recycled motor oils; lube oil aromatic extracts and crude oils such as heavy crude oil, distressed crude oils and similar materials that might otherwise be sent to a hydrocracker or diverted into the blending pool for a prior art high sulfur heavy (residual) marine fuel oil. Examples of Diluent Materials considered non-hydrocarbon based materials include: residual water (i.e. water absorbed from the humidity in the air or water that is miscible or solubilized, sometimes as microemulsions, into the hydrocarbons of the Product HMFO), fuel additives which can include, but are not limited to detergents, viscosity modifiers, pour point depressants, lubricity modifiers, de-hazers (e.g. alkoxylated phenol formaldehyde polymers), antifoaming agents (e.g. polyether modified polysiloxanes); ignition improvers; anti rust agents (e.g. succinic acid ester derivatives); corrosion inhibitors; anti-wear additives, anti-oxidants (e.g. phenolic compounds and derivatives), coating agents and surface modifiers, metal deactivators, static dissipating agents, ionic and nonionic surfactants, stabilizers, cosmetic colorants and odorants and mixtures of these. A third group of Diluent Materials may include suspended solids or fine particulate materials that are present because of the handling, storage and transport of the Product HMFO or the Heavy Marine Fuel Composition, including but not limited to: carbon or hydrocarbon solids (e.g. coke, graphitic solids, or micro-agglomerated asphaltenes), iron rust and other oxidative corrosion solids, fine bulk metal particles, paint or surface coating particles, plastic or polymeric or elastomer or rubber particles (e.g. resulting from the degradation of gaskets, valve parts, etc . . . ), catalyst fines, ceramic or mineral particles, sand, clay, and other earthen particles, bacteria and other biologically generated solids, and mixtures of these that may be present as suspended particles, but otherwise don't detract from the merchantable quality of the Heavy Marine Fuel Composition as an ISO 8217 (2017) compliant heavy (residual) marine fuel.

The blend of Product HMFO and Diluent Materials must be of merchantable quality as a low sulfur heavy (residual) marine fuel. That is the blend must be suitable for the intended use as heavy marine bunker fuel and generally be fungible as a bunker fuel for ocean going ships. Preferably the Heavy Marine Fuel Composition must retain the bulk physical properties required of an ISO 8217 (2017) compliant residual marine fuel oil and a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754) so that the material qualifies as MARPOL Annex VI Low Sulfur Heavy Marine Fuel Oil (LS-HMFO). The sulfur content of the Product HMFO can be lower than 0.5% wt. (i.e. below 0.1%wt sulfur (ISO 14596 or ISO 8754)) to qualify as a MARPOL Annex VI compliant Ultra-Low Sulfur Heavy Marine Fuel Oil (ULS-HMFO) and a Heavy Marine Fuel Composition likewise can be formulated to qualify as a MARPOL Annex VI compliant ULS-HMFO suitable for use as marine bunker fuel in the ECA zones. The Heavy Marine Fuel Composition of the present invention must meet those internationally accepted standards for the bulk properties of residual marine fuel oils including: a maximum kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C. ; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass %, and also preferably a maximum aluminum plus silicon (ISO 10478) content of 60 mg/kg.

Production Plant Description: Turning now to a more detailed illustrative embodiment of a production plant implementing both the core process and the microwave treatment processes disclosed, FIGS. 4 and 5 show a schematic for a production plant implementing the core process described above combined with a pre-treatment microwave treatment unit (MTU) (FIG. 4, item 2) or a post-treatment MTU (FIG. 5, item 18), the combination which will reduce the environmental contaminates in a Feedstock HMFO to produce a Product HMFO that is ISO 8217 (2017) compliant and with the desired properties of a merchantable HMFO.

It will be appreciated by one of skill in the art that additional alternative embodiments for the core process and the MTU may involve multiple vessels and reactors even though only one of each is shown. Variations using multiple vessels/reactors are contemplated by the present invention but are not illustrated in greater detail for simplicity sake.

The Reactor System (11) for the core process is described in greater detail below and using multiple vessels process has been described. It will be noted by one of skill in the art that in FIGS. 4 and 5, portions of the production plant with similar function and operation have been assigned the same reference number. This has been done for convenience and succinctness only and differences between FIG. 4 and FIG. 5 are duly noted and explained below.

In FIGS. 4 and 5, Feedstock HMFO (A) is fed from outside the battery limits (OSBL) to the Oil Feed Surge Drum (1) that receives feed from outside the battery limits (OSBL) and provides surge volume adequate to ensure smooth operation of the unit. Water entrained in the feed is removed from the HMFO with the water being discharged a stream (1 c) for treatment OSBL.

As shown in FIG. 4, the Feedstock HMFO (A) is withdrawn from the Oil Feed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and sent to the MTU 2 as a pretreatment step. The pre-treated Feedstock HMFO is pressurized to a pressure required for the process. The pressurized HMFO (A′) then passes through line (3 a) to the Oil Feed/Product Heat Exchanger (5) where the pressurized HMFO (A′) is partially heated by the Product HMFO (B). The pressurized Feedstock HMFO (A′) passing through line (5 a) is further heated against the effluent from the Reactor System (E) in the Reactor Feed/Effluent Heat Exchanger (7).

As shown in FIG. 5, the Feedstock HMFO (A) is withdrawn from the Oil Feed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and is pressurized to a pressure required for the core process. The pressurized HMFO (A′) then passes through line (3 a) to the Oil Feed/Product Heat Exchanger (5) where the pressurized HMFO (A′) is partially heated by the Product HMFO (B). The pressurized Feedstock HMFO (A′) passing through line (5 a) is further heated against the effluent from the Reactor System (E) in the Reactor Feed/Effluent Heat Exchanger (7).

In both FIG. 4 and FIG. 5, the heated and pressurized Feedstock HMFO (A″) in line (7 a) is then mixed with Activating Gas (C) provided via line (23 c) at Mixing Point (X) to form a Feedstock Mixture (D). The mixing point (X) can be any well know gas/liquid mixing system or entrainment mechanism well known to one skilled in the art.

The Feedstock Mixture (D) passes through line (9 a) to the Reactor Feed Furnace (9) where the Feedstock Mixture (D) is heated to the specified process temperature. The Reactor Feed Furnace (9) may be a fired heater furnace or any other kind to type of heater as known to one of skill in the art if it will raise the temperature of the Feedstock mixture to the desired temperature for the process conditions.

The heated Feedstock Mixture (D′) exits the Reactor Feed Furnace (9) via line 9 b and is fed into the Reactor System (11). The heated Feedstock Mixture (D′) enters the Reactor System (11) where environmental contaminates, such a sulfur, nitrogen, and metals are preferentially removed from the Feedstock HMFO component of the heated Feedstock Mixture. The Reactor System contains a catalyst which preferentially removes the sulfur compounds in the Feedstock HMFO component by reacting them with hydrogen in the Activating Gas to form hydrogen sulfide. The Reactor System will also achieve demetallization, denitrogenation, and a certain amount of ring opening hydrogenation of the complex aromatics and asphaltenes, however minimal hydrocracking of hydrocarbons should take place. The process conditions of hydrogen partial pressure, reaction pressure, temperature and residence time as measured by liquid hourly velocity are optimized to achieve desired final product quality. A more detailed discussion of the Reactor System, the catalyst, the process conditions, and other aspects of the process are contained below in the “Reactor System Description.”

The Reactor System Effluent (E) exits the Reactor System (11) via line (11 a) and exchanges heat against the pressurized and partially heats the Feedstock HMFO (A′) in the Reactor Feed/Effluent Exchanger (7). The partially cooled Reactor System Effluent (E′) then flows via line (11 c) to the Hot Separator (13).

The Hot Separator (13) separates the gaseous components of the Reactor System Effluent (F) which are directed to line (13 a) from the liquid components of the Reactor System effluent (G) which are directed to line (13 b). The gaseous components of the Reactor System effluent in line (13 a) are cooled against air in the Hot Separator Vapor Air Cooler (15) and then flow via line (15 a) to the Cold Separator (17).

The Cold Separator (17) further separates any remaining gaseous components from the liquid components in the cooled gaseous components of the Reactor System Effluent (F′). The gaseous components from the Cold Separator (F″) are directed to line (17 a) and fed onto the Amine Absorber (21). The Cold Separator (17) also separates any remaining Cold Separator hydrocarbon liquids (H) in line (17 b) from any Cold Separator condensed liquid water (I). The Cold Separator condensed liquid water (I) is sent OSBL via line (17 c) for treatment.

In FIG. 4, the hydrocarbon liquid components of the Reactor System effluent from the Hot Separator (G) in line (13 b) and the Cold Separator hydrocarbon liquids (H) in line (17 b) are combined and are fed to the Oil Product Stripper System (19). The Oil Product Stripper System (19) removes any residual hydrogen and hydrogen sulfide from the Product HMFO (B) which is discharged in line (19 b) to storage OSBL. The vent stream (M) from the Oil Product Stripper in line (19 a) may be sent to the fuel gas system or to the flare system that are OSBL.

In FIG. 5, the hydrocarbon liquid components of the Reactor System effluent from the Hot Separator (G) in line (13 b) and the Cold Separator hydrocarbon liquids (H) in line (17 b) are combined and are fed to the MTU (18) prior to being sent to the Oil Product Stripper System (19). The Oil Product Stripper System (19) removes any residual hydrogen and hydrogen sulfide from the Product HMFO (B) which is discharged in line (19 b) to storage OSBL. It is also contemplated that a second draw (not shown) may be included to withdraw a distillate product, preferably a middle to heavy distillate. The vent stream (M) from the Oil Product Stripper in line (19 a) may be sent to the fuel gas system or to the flare system that are OSBL.

An alternative embodiment not shown in FIG. 5, but well within the skill of one in the art, would be to relocate the MTU (18) from the line prior to the Oil Product Stripper (19) to a location downstream of the Oil Product Stripper (19). Such a relocation of the MTU (18) to line (19 b) will allow for the microwave treatment of the final product HMFO prior to being sent to storage OSBL. This location is practicable because the MTU may induce changes in TAN and viscosity without substantial production of light hydrocarbons (i.e. minimal cracking). The MTU may also impart an additional amount of stability to the product HMFO.

The gaseous components from the Cold Separator (F″) in line (17 a) contain a mixture of hydrogen, hydrogen sulfide and light hydrocarbons (mostly methane and ethane). This vapor stream (17 a) feeds an Amine Absorber (21) where it is contacted against Lean Amine (J) provided OSBL via line (21 a) to the Amine Absorber (21) to remove hydrogen sulfide from the gases making up the Activating Gas recycle stream (C′). Rich amine (K) which has absorbed hydrogen sulfide exits the bottom of the Amine Absorber (21) and is sent OSBL via line (21 b) for amine regeneration and sulfur recovery.

The Amine Absorber overhead vapor in line (21 c) is preferably recycled to the process as a Recycle Activating Gas (C′) via the Recycle Compressor (23) and line (23 a) where it is mixed with the Makeup Activating Gas (C″) provided OSBL by line (23 b). This mixture of Recycle Activating Gas (C′) and Makeup Activating Gas (C″) to form the Activating Gas (C) utilized in the process via line (23 c) as noted above. A Scrubbed Purge Gas stream (H) is taken from the Amine Absorber overhead vapor line (21 c) and sent via line (21 d) to OSBL to prevent the buildup of light hydrocarbons or other non-condensables.

Reactor System Description: The core process Reactor System (11) illustrated in FIG. 4 and FIG. 5 comprises a single reactor vessel loaded with the process catalyst and sufficient controls, valves and sensors as one of skill in the art would readily appreciate.

Alternative Reactor Systems in which more than one reactor vessel may be utilized in parallel or in a cascading series can easily be substituted for the single reactor vessel Reactor System 11 shown. In such an embodiment, each reactor vessel is similarly loaded with process catalyst and can be provided the heated Feed Mixture (D′) via a common line. The effluent from each of the three reactors is recombined in line and forms a combined Reactor Effluent (E) for further processing as described above. The illustrated arrangement will allow the three reactors to carry out the process effectively multiplying the hydraulic capacity of the overall Reactor System. Control valves and isolation valves may also prevent feed from entering one reactor vessel but not another reactor vessel. In this way one reactor can be by-passed and placed off-line for maintenance and reloading of catalyst while the remaining reactors continues to receive heated Feedstock Mixture (D′). It will be appreciated by one of skill in the art this arrangement of reactor vessels in parallel is not limited in number to three, but multiple additional reactor vessels can be added. The only limitation to the number of parallel reactor vessels is plot spacing and the ability to provide heated Feedstock Mixture (D′) to each active reactor.

In another illustrative embodiment cascading reactor vessels are loaded with process catalyst with the same or different activities toward metals, sulfur or other environmental contaminates to be removed. For example, one reactor may be loaded with a highly active demetallization catalyst, a second subsequent or downstream reactor may be loaded with a balanced demetallization/desulfurizing catalyst, and reactor downstream from the second reactor may be loaded with a highly active desulfurization catalyst. This allows for greater control and balance in process conditions (temperature, pressure, space flow velocity, etc . . . ) so it is tailored for each catalyst. In this way one can optimize the parameters in each reactor depending upon the material being fed to that specific reactor/catalyst combination and minimize the hydrocracking reactions. As with the prior illustrative embodiment, multiple cascading series of reactors can be utilized in parallel and in this way the benefits of such an arrangement noted above (i.e. allow one series to be “online” while the other series is “off line” for maintenance or allow increased plant capacity).

The reactor(s) that form the Reactor System may be fixed bed, ebulliated bed or slurry bed or a combination. As envisioned, fixed bed reactors are preferred as these are easier to operate and maintain.

The reactor vessel in the Reactor System is loaded with one or more process catalysts. The exact design of the process catalyst system is a function of feedstock properties, product requirements and operating constraints and optimization of the process catalyst can be carried out by routine trial and error by one of ordinary skill in the art.

The process catalyst(s) comprise at least one metal selected from the group consisting of the metals each belonging to the groups 6, 8, 9 and 10 of the Periodic Table, and more preferably a mixed transition metal catalyst such as Ni—Mo, Co—Mo, Ni—W or Ni—Co—Mo are utilized. The metal is preferably supported on a porous inorganic oxide catalyst carrier. The porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier. The preferred porous inorganic oxide catalyst carrier is alumina. The pore size and metal loadings on the carrier may be systematically varied and tested with the desired feedstock and process conditions to optimize the properties of the Product HMFO. Such activities are well known and routine to one of skill in the art. Catalyst in the fixed bed reactor(s) may be dense-loaded or sock-loaded.

The catalyst selection utilized within and for loading the Reactor System may be preferential to desulfurization by designing a catalyst loading scheme that results in the Feedstock mixture first contacting a catalyst bed that with a catalyst preferential to demetallization followed downstream by a bed of catalyst with mixed activity for demetallization and desulfurization followed downstream by a catalyst bed with high desulfurization activity. In effect the first bed with high demetallization activity acts as a guard bed for the desulfurization bed.

The objective of the Reactor System is to treat the Feedstock HMFO at the severity required to meet the Product HMFO specification. Demetallization, denitrogenation and hydrocarbon hydrogenation reactions may also occur to some extent when the process conditions are optimized so performing the Reactor System achieves the required level of desulfurization. Hydrocracking is preferably minimized to reduce the volume of hydrocarbons formed as by-product hydrocarbons to the process. The objective of the process is to selectively remove the environmental contaminates from Feedstock HMFO and minimize the formation of unnecessary by-product hydrocarbons (C1-C8 hydrocarbons).

The process conditions in each reactor vessel will depend upon the feedstock, the catalyst utilized and the desired final properties of the Product HMFO desired. Variations in conditions are to be expected by one of ordinary skill in the art and these may be determined by pilot plant testing and systematic optimization of the process. With this in mind it has been found that the operating pressure, the indicated operating temperature, the ratio of the Activating Gas to Feedstock HMFO, the partial pressure of hydrogen in the Activating Gas and the space velocity all are important parameters to consider. The operating pressure of the Reactor System should be in the range of 250 psig and 3000 psig, preferably between 1000 psig and 2500 psig and more preferably between 1500 psig and 2200 psig. The indicated operating temperature of the Reactor System should be 500° F. to 900 F, preferably between 650° F. and 850° F. and more preferably between 680° F. and 800 F. The ratio of the quantity of the Activating Gas to the quantity of Feedstock HMFO should be in the range of 250 scf gas/bbl of Feedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO, preferably between 2000 scf gas/bbl of Feedstock HMFO to 5000 scf gas/bbl of Feedstock HMFO and more preferably between 2500 scf gas/bbl of Feedstock HMFO to 4500 scf gas/bbl of Feedstock HMFO. The Activating Gas should be selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane, so Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the Activating Gas mixture (P) and preferably wherein the Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 95% of the total pressure of the Activating Gas mixture (P). The Activating Gas may have a hydrogen mole fraction in the range between 80% of the total moles of Activating Gas mixture and more preferably wherein the Activating Gas has a hydrogen mole fraction between 80% and 99% of the total moles of Activating Gas mixture. The liquid hourly space velocity within the Reactor System should be between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst; preferably between 0.08 oil/hour/m³ catalyst and 0.5 oil/hour/m³ catalyst and more preferably between 0.1 oil/hour/m³ catalyst and 0.3 oil/hour/m³ catalyst to achieve deep desulfurization with product sulfur levels below 0.1 ppmw.

The hydraulic capacity rate of the Reactor System should be between 100 bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day, preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl of Feedstock HMFO/day, more preferably between 5,000 bbl of Feedstock HMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferably between 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of Feedstock HMFO/day. The desired hydraulic capacity may be achieved in a single reactor vessel Reactor System or in a multiple reactor vessel Reactor System.

These examples will provide one skilled in the art with a more specific illustrative embodiment for conducting the process disclosed and claimed herein:

EXAMPLE 1

Overview: The purpose of a pilot test run is to demonstrate that feedstock HMFO can be processed through a reactor loaded with commercially available catalysts at specified conditions to remove environmental contaminates, specifically sulfur and other contaminants from the HMFO to produce a product HMFO that is MARPOL compliant, that is production of a Low Sulfur Heavy Marine Fuel Oil (LS-HMFO) or Ultra-Low Sulfur Heavy Marine Fuel Oil (USL-HMFO).

Pilot Unit Set Up: The pilot unit will be set up with two 434 cm³ reactors arranged in series to process the feedstock HMFO. The lead reactor will be loaded with a blend of a commercially available hydro-demetallization (HDM) catalyst and a commercially available hydro-transition (HDT) catalyst. One of skill in the art will appreciate that the HDT catalyst layer may be formed and optimized using a mixture of HDM and HDS catalysts combined with an inert material to achieve the desired intermediate/transition activity levels. The second reactor will be loaded with a blend of the commercially available hydro-transition (HDT) and a commercially available hydrodesulfurization (HDS). Alternatively, one can load the second reactor simply with a commercially hydrodesulfurization (HDS) catalyst. One of skill in the art will appreciate that the specific feed properties of the Feedstock HMFO may affect the proportion of HDM, HDT and HDS catalysts in the reactor system. A systematic process of testing different combinations with the same feed will yield the optimized catalyst combination for any feedstock and reaction conditions. For this example, the first reactor will be loaded with ⅔ hydro-demetallization catalyst and ⅓ hydro-transition catalyst. The second reactor will be loaded with all hydrodesulfurization catalyst. The catalysts in each reactor will be mixed with glass beads (approximately 50% by volume) to improve liquid distribution and better control reactor temperature. For this pilot test run, one should use these commercially available catalysts: HDM: Albemarle KFR 20 series or equivalent; HDT: Albemarle KFR 30 series or equivalent; HDS: Albemarle KFR 50 or KFR 70 or equivalent. Once set up of the pilot unit is complete, the catalyst can be activated by sulfiding the catalyst using dimethyldisulfide (DMDS) in a manner well known to one of skill in the art.

Pilot Unit Operation: Upon completion of the activating step, the pilot unit will be ready to receive the feedstock HMFO and Activating Gas feed. For the present example, the Activating Gas can be technical grade or better hydrogen gas. The mixed Feedstock HMFO and Activating Gas will be provided to the pilot plant at rates and operating conditions as specified: Oil Feed Rate: 108.5 ml/h (space velocity=0.25/h); Hydrogen/Oil Ratio: 570 Nm³/m³ (3200 scf/bbl); Reactor Temperature: 372° C. (702° F.); Reactor Outlet Pressure:13.8 MPa(g) (2000 psig).

One of skill in the art will know that the rates and conditions may be systematically adjusted and optimized depending upon feed properties to achieve the desired product requirements. The unit will be brought to a steady state for each condition and full samples taken so analytical tests can be completed. Material balance for each condition should be closed before moving to the next condition.

Expected impacts on the Feedstock HMFO properties are: Sulfur Content (wt %): Reduced by at least 80%; Metals Content (wt %): Reduced by at least 80%; MCR/Asphaltene Content (wt %): Reduced by at least 30%; Nitrogen Content (wt %): Reduced by at least 20%; C1-Naphtha Yield (wt%): Not over 3.0% and preferably not over 1.0%.

Process conditions in the Pilot Unit can be systematically adjusted as per Table 4 to assess the impact of process conditions and optimize the performance of the process for the specific catalyst and feedstock HMFO utilized.

TABLE 4 Optimization of Process Conditions HC Feed Rate (ml/h), Nm³ H₂/m³ oil/ Temp Pressure Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.) (MPa(g)/psig) Baseline 108.5 [0.25] 570/3200 372/702 13.8/2000 T1 108.5 [0.25] 570/3200 362/684 13.8/2000 T2 108.5 [0.25] 570/3200 382/720 13.8/2000 L1 130.2 [0.30] 570/3200 372/702 13.8/2000 L2  86.8 [0.20] 570/3200 372/702 13.8/2000 H1 108.5 [0.25] 500/2810 372/702 13.8/2000 H2 108.5 [0.25] 640/3590 372/702 13.8/2000 S1  65.1 [0.15] 620/3480 385/725 15.2/2200

In this way, the conditions of the pilot unit can be optimized to achieve less than 0.5% wt. sulfur product HMFO and preferably a 0.1% wt. sulfur product HMFO. Conditions for producing ULS-HMFO (i.e. 0.1% wt. sulfur product HMFO) will be: Feedstock HMFO Feed Rate: 65.1 ml/h (space velocity=0.15/h); Hydrogen/Oil Ratio: 620 Nm³/m³ (3480 scf/bbl); Reactor Temperature: 385° C. (725° F.); Reactor Outlet Pressure: 15 MPa(g) (2200 psig)

Table 5 summarizes the anticipated impacts on key properties of HMFO.

TABLE 5 Expected Impact of Process on Key Properties of HMFO Property Minimum Typical Maximum Sulfur Conversion/Removal  80%  90%   98% Metals Conversion/Removal  80%  90%  100% MCR Reduction  30%  50%   70% Asphaltene Reduction  30%  50%   70% Nitrogen Conversion  10%  30%   70% C1 through Naphtha Yield 0.5% 1.0%  4.0% Hydrogen Consumption (scf/bbl) 500 750 1500

Table 6 lists analytical tests to be carried out for the characterization of the Feedstock HMFO and Product HMFO. The analytical tests include those required by ISO for the Feedstock HMFO and the product HMFO to qualify and trade in commerce as ISO compliant residual marine fuels. The additional parameters are provided so that one skilled in the art can understand and appreciate the effectiveness of the inventive process.

TABLE 6 Analytical Tests and Testing Procedures Sulfur Content ISO 8754 or ISO 14596 or ASTM D4294 Density @ 15° C. ISO 3675 or ISO 12185 Kinematic Viscosity ISO 3104 @ 50° C. Pour Point, ° C. ISO 3016 Flash Point, ° C. ISO 2719 CCAI ISO 8217, ANNEX B Ash Content ISO 6245 Total Sediment - Aged ISO 10307-2 Micro Carbon Residue, ISO 10370 mass % H2S, mg/kg IP 570 Acid Number ASTM D664 Water ISO 3733 Specific Contaminants IP 501 or IP 470 (unless indicated otherwise) Vanadium or ISO 14597 Sodium Aluminum or ISO 10478 Silicon or ISO 10478 Calcium or IP 500 Zinc or IP 500 Phosphorous IP 500 Nickle Iron Distillation ASTM D7169 C:H Ratio ASTM D3178 SARA Analysis ASTM D2007 Asphaltenes, wt % ASTM D6560 Total Nitrogen ASTM D5762 Vent Gas Component FID Gas Chromatography or Analysis comparable

Table 7 contains the Feedstock HMFO analytical test results and the Product HMFO analytical test results expected from the inventive process that indicate the production of a LS HMFO. It will be noted by one of skill in the art that under the conditions, the levels of hydrocarbon cracking will be minimized to levels substantially lower than 10%, more preferably less than 5% and even more preferably less than 1% of the total mass balance.

TABLE 7 Analytical Results Feedstock Product HMFO HMFO Sulfur Content, mass %   3.0   0.3 Density @ 15° C., kg/m³  990  950 ⁽¹⁾ Kinematic Viscosity @ 50° C.,  380  100 ⁽¹⁾ mm²/s Pour Point, ° C.  20  10 Flash Point, ° C.  110  100 ⁽¹⁾ CCAI  850  820 Ash Content, mass %   0.1   0.0 Total Sediment - Aged, mass %   0.1   0.0 Micro Carbon Residue, mass %  13.0   6.5 H2S, mg/kg   0   0 Acid Number, mg KO/g   1   0.5 Water, vol %   0.5   0 Specific Contaminants, mg/kg Vanadium  180  20 Sodium  30   1 Aluminum  10   1 Silicon  30   3 Calcium  15   1 Zinc   7   1 Phosphorous   2   0 Nickle  40   5 Iron  20   2 Distillation, ° C./° F. IBP 160/320  120/248   5% wt 235/455  225/437  10% wt 290/554  270/518  30% wt 410/770  370/698  50% wt 540/1004 470/878  70% wt 650/1202 580/1076 90% wt 735/1355 660/1220 FBP 820/1508 730/1346 C:H Ratio (ASTM D3178)   1.2   1.3 SARA Analysis Saturates  16  22 Aromatics  50  50 Resins  28  25 Asphaltenes   6   3 Asphaltenes, wt %   6.0   2.5 Total Nitrogen, mg/kg 4000 3000 Note: ⁽¹⁾ property will be adjusted to a higher value by post process removal of light material via distillation or stripping from product HMFO.

The product HMFO produced by the inventive process will reach ULS HMFO limits (i.e. 0.1% wt. sulfur product HMFO) by systematic variation of the process parameters, for example by a lower space velocity or by using a Feedstock HMFO with a lower initial sulfur content.

EXAMPLE 2 RMG-380 HMFO

Pilot Unit Set Up: A pilot unit was set up as noted above in Example 1 with these changes: the first reactor was loaded with: as the first (upper) layer encountered by the feedstock 70% vol Albemarle KFR 20 series hydro-demetallization catalyst and 30% vol Albemarle KFR 30 series hydro-transition catalyst as the second (lower) layer. The second reactor was loaded with 20% Albemarle KFR 30 series hydrotransition catalyst as the first (upper) layer and 80% vol hydrodesulfurization catalyst as the second (lower) layer. The catalyst was activated by sulfiding the catalyst with dimethyldisulfide (DMDS) in a manner well known to one of skill in the art.

Pilot Unit Operation: Upon completion of the activating step, the pilot unit was ready to receive the feedstock HMFO and Activating Gas feed. The Activating Gas was technical grade or better hydrogen gas. The Feedstock HMFO was a commercially available and merchantable ISO 8217 (2017) compliant HMFO, except for a high sulfur content (2.9 wt %). The mixed Feedstock HMFO and Activating Gas was provided to the pilot plant at rates and conditions as specified in Table 8 below. The conditions were varied to optimize the level of sulfur in the product HMFO material.

TABLE 8 Process Conditions Product HC Feed Pressure HMFO Rate (ml/h), Nm³ H₂/m³ oil/ Temp (MPa(g)/ Sulfur Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.) psig) % wt. Baseline 108.5 [0.25] 570/3200 371/700 13.8/2000 0.24 T1 108.5 [0.25] 570/3200 362/684 13.8/2000 0.53 T2 108.5 [0.25] 570/3200 382/720 13.8/2000 0.15 L1 130.2 [0.30] 570/3200 372/702 13.8/2000 0.53 S1  65.1 [0.15] 620/3480 385/725 15.2/2200 0.10 P1 108.5 [0.25] 570/3200 371/700 /1700 0.56 T2/P1 108.5 [0.25] 570/3200 382/720 /1700 0.46

Analytical data for a representative sample of the feedstock HMFO and representative samples of product HMFO are below:

TABLE 7 Analytical Results - HMFO (RMG-380) Feedstock Product Product Sulfur Content, mass % 2.9 0.3 0.1 Density @ 15° C., kg/m³ 988 932 927 Kinematic Viscosity 382 74 47 @ 50° C., mm²/s Pour Point, ° C. −3 −12 −30 Flash Point, ° C. 116 96 90 CCAI 850 812 814 Ash Content, mass % 0.05 0.0 0.0 Total Sediment - Aged, 0.04 0.0 0.0 mass % Micro Carbon Residue, 11.5 3.3 4.1 mass % H2S, mg/kg 0.6 0 0 Acid Number, mg KO/g 0.3 0.1 >0.05 Water, vol % 0 0.0 0.0 Specific Contaminants, mg/kg Vanadium 138 15 <1 Sodium 25 5 2 Aluminum 21 2 <1 Silicon 16 3 1 Calcium 6 2 <1 Zinc 5 <1 <1 Phosphorous <1 2 1 Nickle 33 23 2 Iron 24 8 1 Distillation, ° C./° F. IBP 178/352  168/334  161/322   5% wt 258/496  235/455  230/446  10% wt 298/569  270/518  264/507  30% wt 395/743  360/680  351/664  50% wt 517/962  461/862  439/822  70% wt 633/1172 572/1062 552/1026 90% wt >720/>1328 694/1281 679/1254 FBP >720/>1328 >720/>1328 >720/>1328 C:H Ratio (ASTM D3178) 1.2 1.3 1.3 SARA Analysis Saturates 25.2 28.4 29.4 Aromatics 50.2 61.0 62.7 Resins 18.6 6.0 5.8 Asphaltenes 6.0 4.6 2.1 Asphaltenes, wt % 6.0 4.6 2.1 Total Nitrogen, mg/kg 3300 1700 1600

In Table 7, both feedstock HMFO and product HMFO exhibited observed bulk properties consistent with ISO 8217 (2017) for a merchantable residual marine fuel oil, except that the sulfur content of the product HMFO was reduced as noted above when compared to the feedstock HMFO.

One of skill in the art will appreciate that the above product HMFO produced by the inventive process has achieved not only an ISO 8217 (2017) compliant LS HMFO (i.e. 0.5%wt. sulfur) but also an ISO 8217 (2017) compliant ULS HMFO limits (i.e. 0.1% wt. sulfur) product HMFO.

EXAMPLE 3 RMK-500 HMFO

The feedstock to the pilot reactor utilized in example 2 above was changed to a commercially available and merchantable ISO 8217 (2017) RMK-500 compliant HMFO, except that it has high environmental contaminates (i.e. sulfur (3.3 wt %)). Other bulk characteristic of the RMK-500 feedstock high sulfur HMFO are provide below:

TABLE 8 Analytical Results- Feedstock HMFO (RMK-500) Sulfur Content, mass % 3.3 Density @ 15° C., kg/m³ 1006 Kinematic Viscosity @ 50° C., mm²/s 500

The mixed Feedstock (RMK-500) HMFO and Activating Gas was provided to the pilot plant at rates and conditions and the resulting sulfur levels achieved in the table below

TABLE 9 Process Conditions Product HC Feed Pressure (RMK-500) Rate (ml/h), Nm³ H₂/m³ oil/ Temp (MPa(g)/ sulfur Case [LHSV(/h)] scf H²/bbl oil (° C./° F.) psig) % wt. A 108.5 [0.25] 640/3600 377/710 13.8/2000 0.57 B  95.5 [0.22] 640/3600 390/735 13.8/2000 0.41 C  95.5 [0.22] 640/3600 390/735 11.7/1700 0.44 D  95.5 [0.22] 640/3600 393/740 10.3/1500 0.61 E  95.5 [0.22] 640/3600 393/740 17.2/2500 0.37 F  95.5 [0.22] 640/3600 393/740  8.3/1200 0.70 G  95.5 [0.22] 640/3600 416/780  8.3/1200

The resulting product (RMK-500) HMFO exhibited observed bulk properties consistent with the feedstock (RMK-500) HMFO, except that the sulfur content was reduced as noted in the above table.

One of skill in the art will appreciate that the above product HMFO produced by the inventive process has achieved a LS HMFO (i.e. 0.5%wt. sulfur) product HMFO having bulk characteristics of a ISO 8217 (2017) compliant RMK-500 residual fuel oil. It will also be appreciated that the process can be successfully carried out under non-hydrocracking conditions (i.e. lower temperature and pressure) that substantially reduce the hydrocracking of the feedstock material. When conditions were increased to much higher pressure (Example E) a product with a lower sulfur content was achieved, however it was observed that there was an increase in light hydrocarbons and wild naphtha production.

This prophetic example will provide one skilled in the art with a more specific illustrative embodiment for conducting the processes disclosed:

Prophetic Example of Microwave Treatment Unit Operation: To exemplify the invention, experiments can be carried out using a lab microwave oven at a frequency of 2.45 GHz and a maximum power of 1000 W, operating in a continuous or pulsed mode and equipped with programmable control devices and a thermocouple and fiber optic temperature sensor to measure temperatures. The reaction system used comprises a 3-mouth glass flask coated in a microwave (MW) transparent thermal insulator known as kaolin (aluminum-silicate), equipped with mechanical stirring from the well to the temperature sensor via fiber optics then from the condenser to the water chilled flush back maintained outside the microwave cavity. The operating conditions used to process the petroleum will be the normal power of the 200 W, 300 W and 1000 W microwave oven and continuous and pulsed microwave oven operating mode. The absorbent used will be a spent hydroprocessing sulfided catalyst utilized in the transition section, in a catalyst-to-oil ration of 0.3:1. The initial HMFO temperature will be about room temperature or equal to 25° C. The final nominal temperature of the product between 230° C. and 300° C. The reactionary system will have mechanical stirring and one output of the reactor was hooked up to a water-chilled reflux condenser. In this example, in the pulsed operating method of the source of the microwave oven, the nominal power will be distributed over time in constant pulses of 1000 W. The frequency of pulses in this equipment will be constant at 35 pulses/min. equivalent to 0.58 cycles or 1.7 s/cycle. For an average power of 200 W applied to a system pulsed with 1000 W each pulse lasts 0.34 seconds and powered off intervals of 1.37 seconds. The catalysts chosen for this study were hydro refining catalysts, HDR, alumina supported, after being used in an industrial unit or pilot plant (PP). These catalysts, NiMo or CoMo type, with molybdenum sulfate as an active phase, also have high activity a microwave absorbers. With these catalysts the aim was to conjugate in a synergic and localized form in the same active sites, the remaining catalytic activity during the active phase of the molybdenum sulfate with its high capacity to absorb microwaves. If hydrogen will be present during the microwave treatment the reaction zone will be at a pressure ranging from one atmosphere to 400 psig.

The load of hydrocarbons assessed in this example will be the Feedstock HMFO or the product HMFO described above. It is expected that the TAN (and the potential to form coke during hydroprocessing) will decrease and the API gravity of the HMFO material will be increased. In addition, the viscosity of the HMFO is modified in such a manner to make it less viscous. In this way a highly viscous residual based high sulfur Feedstock HMFO otherwise ISO 8217 (2017) compliant, such as RMG 500 (Kinematic Viscosity of 500 at 50° C.) or RMG700 (Kinematic Viscosity of 500) at 50° C. or even RMK500 or 700, may be more easily introduced in the core process and processed with less formation of coke and other particles that may cause a rapid increase in reactor backpres sure. As part of the post Core Process treatment of the Product HMFO, the described process can be carried out to condition the Product HMFO for easier transport and handling, increased compatibility and stability when blended with other marine fuel materials (i.e. MGO or MDO), and enhance the value of these materials as low sulfur HMFO.

Table 4 contains the expected analytical test results for (A) Feedstock HMFO; (B) the Core Process Product HMFO and (C) Overall Process (Core+post microwave treatment) from the inventive processes. These results will indicate to one of skill in the art that the production of a ULS HMFO can be achieved. It will be noted by one of skill in the art that under the conditions, the levels of hydrocarbon cracking will be minimized to levels substantially lower than 10%, more preferably less than 5% and even more preferably less than 1% of the total mass balance.

TABLE 4 Analytical Results A B C Sulfur Content, mass %   3.0 Less than 0.5 Less than 0.1 Density @ 15° C., kg/m³  990  950 ⁽¹⁾  950 ⁽¹⁾ Kinematic Viscosity @  380  100 ⁽¹⁾  100 ⁽¹⁾ 50° C., mm²/s Pour Point, ° C.  20  10  10 Flash Point, ° C.  110  100 ⁽¹⁾  100 ⁽¹⁾ CCAI  850  820  820 Ash Content, mass %   0.1   0.0   0.0 Total Sediment - Aged,   0.1   0.0   0.0 mass % Micro Carbon Residue,  13.0   6.5   6.5 mass % H2S, mg/kg   0   0   0 Acid Number, mg KO/g   1   0.5 Less than 0.5 Water, vol %   0.5   0   0 Specific Contaminants, mg/kg Vanadium  180  20  20 Sodium  30   1   1 Aluminum  10   1   1 Silicon  30   3   3 Calcium  15   1   1 Zinc   7   1   1 Phosphorous   2   0   0 Nickle  40   5   5 Iron  20   2   2 Distillation, ° C./° F. IBP 160/320  120/248  120/248   5% wt 235/455  225/437  225/437  10% wt 290/554  270/518  270/518  30% wt 410/770  370/698  370/698  50% wt 540/1004 470/878  470/878  70% wt 650/1202 580/1076 580/1076 90% wt 735/1355 660/1220 660/1220 FBP 820/1508 730/1346 730/1346 C:H Ratio (ASTM D3178)   1.2   1.3   1.3 SARA Analysis Saturates  16  22  22 Aromatics  50  50  50 Resins  28  25  25 Asphaltenes   6   3   3 Asphaltenes, wt %   6.0   2.5   2.5 Total Nitrogen, mg/kg 4000 3000 3000 Note: (1) property will be adjusted to a higher value by post process removal of light material via distillation or stripping from product HMFO.

It will be appreciated by those skilled in the art that changes could be made to the illustrative embodiments described above without departing from the broad inventive concepts thereof. It is understood, therefore, that the inventive concepts disclosed are not limited to the illustrative embodiments or examples disclosed, but it is intended to cover modifications within the scope of the inventive concepts as defined by the claims. 

1. A process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process comprising: contacting a Feedstock Heavy Marine Fuel Oil with microwave energy having a frequency selected from the group consisting of 915 MHz and 2450 MHz, in the presence of microwave absorbent material to give a pre-treated Feedstock Heavy Marine Fuel Oil; mixing a quantity of the pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under reactive conditions to form a Process Mixture from said Feedstock Mixture; receiving said Process Mixture and separating the Product Heavy Marine Fuel Oil liquid components of the Process Mixture from the gaseous components and by-product hydrocarbon components of the Process Mixture and, discharging the Product Heavy Marine Fuel Oil.
 2. The process of claim 1 wherein said Feedstock Heavy Marine Fuel Oil complies with ISO 8217 (2017) and has a sulfur content (ISO 14596 or ISO 8754) between the range of 5.0 mass % to 1.0 mass %.
 3. The process of claim 1, wherein said Feedstock Heavy Marine Fuel Oil has bulk properties of: a maximum of kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass %.
 4. The process of claim 1, wherein the microwave absorbent material is selected from the group consisting of metallic oxides, sulfates, coking fines tailings; compounds containing nanostructured materials such as nanofibers and nanotubes; catalysts or mixtures of catalysts disposed of at fluid catalytic cracking units; catalysts or mixtures of catalysts disposed of at hydrotreatment units, comprised of transition metals (such as Co, Mo, Ni, etc.), supported on refractory oxides which may be chosen from among alumina, silica, titanium, zirconium and/or mixtures, used hydrodesulfurization catalysts and combinations thereof.
 5. The process of claim 1, wherein the catalyst comprises: a porous inorganic oxide catalyst carrier and a transition metal catalyst, wherein the porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier, and wherein the transition metal catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table and wherein the Activating Gas is selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane, such that Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the Activating Gas mixture (P).
 6. The process of claim 1, wherein the reactive conditions comprise: the ratio of the quantity of the Activating Gas to the quantity of Feedstock Heavy Marine Fuel Oil is in the range of 250 scf gas/bbl of Feedstock Heavy Marine Fuel Oil to 10,000 scf gas/bbl of Feedstock Heavy Marine Fuel Oil; a the total pressure is between of 250 psig and 3000 psig; and, the indicated temperature is between of 500° F. to 900° F., and, wherein the liquid hourly space velocity is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst.
 7. A process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process comprising: mixing a quantity of Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under reactive conditions to form a Process Mixture from said Feedstock Mixture; receiving said Process Mixture and separating the liquid components of the Process Mixture from the bulk gaseous components of the Process Mixture; receiving said liquid components and contacting the liquid components with a microwave energy having a frequency selected from the group consisting of 915 MHz and 2450 MHz, in the presence of microwave absorbent material; subsequently separating any residual gaseous components and by-product hydrocarbon components from the Product Heavy Marine Fuel Oil; and, discharging the Product Heavy Marine Fuel Oil.
 8. The process of claim 7 wherein said Feedstock Heavy Marine Fuel Oil complies with ISO8217:2017 and has a sulfur content (ISO 14596 or ISO 8754) between the range of 5.0 mass % to 1.0 mass %.
 9. The process of claim 7, wherein said Feedstock Heavy Marine Fuel Oil has bulk properties of: a maximum of kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass %.
 10. The process of claim 7, wherein the microwave absorbant material is selected from the group consisting of metallic oxides, sulfates, coking fines tailings; compounds containing nanostructured materials such as nanofibers and nanotubes; catalysts or mixtures of catalysts disposed of at fluid catalytic cracking units; catalysts or mixtures of catalysts disposed of at hydrotreatment units, comprised of transition metals (such as Co, Mo, Ni, etc.), supported on refractory oxides which may be chosen from among alumina, silica, titanium, zirconium and/or mixtures, used hydrodesulfurization catalysts and combinations thereof.
 11. The process of claim 7, wherein the catalyst comprises: a porous inorganic oxide catalyst carrier and a transition metal catalyst, wherein the porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier, and wherein the transition metal catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table; and wherein the Activating Gas is selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane, such that Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the Activating Gas mixture (P).
 12. The process of claim 11, wherein the reactive conditions comprise: the ratio of the quantity of the Activating Gas to the quantity of Feedstock Heavy Marine Fuel Oil is in the range of 250 scf gas/bbl of Feedstock Heavy Marine Fuel Oil to 10,000 scf gas/bbl of Feedstock Heavy Marine Fuel Oil; a the total pressure is between of 250 psig and 3000 psig; and, the indicated temperature is between of 500 F to 900 F, and, wherein the liquid hourly space velocity is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst.
 13. The process of claim 10, wherein said Product Heavy Marine Fuel Oil complies with ISO 8217 (2017) and has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.01 mass % to 1.0 mass %.
 14. The process of claim 11, wherein said Product Heavy Marine Fuel Oil has bulk properties of: a maximum of kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment—aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue—micro method (ISO 10370) less than 20.00 mass %.
 15. A low sulfur heavy marine fuel composition comprising at least 50% by volume of a hydroprocessed and microwave treated residual marine fuel oil and no more than 50% by volume of Diluent Materials selected from the group consisting of: hydrocarbon materials; non-hydrocarbon materials; and, solid materials and combinations thereof.
 16. The low sulfur heavy marine fuel composition of claim 15, wherein, the hydroprocessed and microwave treated residual marine fuel oil is compliant with ISO 8217 (2017).
 17. The low sulfur heavy marine fuel composition of claim 15 wherein the hydrocarbon materials are selected from the group consisting of: heavy marine fuel oil with a sulfur content (ISO 14596 or ISO 8754) greater than 0.5 wt; distillate based fuels; diesel; gas oil; marine gas oil; marine diesel oil; cutter oil; biodiesel; methanol, ethanol; synthetic hydrocarbons and oils based on gas to liquids technology; Fischer-Tropsch derived oils; synthetic oils based on polyethylene, polypropylene, dimer, trimer and poly butylene; atmospheric residue; vacuum residue; fluid catalytic cracker (FCC) slurry oil; FCC cycle oil; pyrolysis gas oil; cracked light gas oil (CLGO); cracked heavy gas oil (CHGO); light cycle oil (LCO); heavy cycle oil (HCO); thermally cracked residue; coker heavy distillate; bitumen; de-asphalted heavy oil; visbreaker residue; slop oils; asphaltinic oils; used or recycled motor oils; lube oil aromatic extracts; crude oil; heavy crude oil; distressed crude oil; and combination thereof; and wherein the non-hydrocarbon materials are selected from the group consisting of: residual water; detergents; viscosity modifiers; pour point depressants; lubricity modifiers; de-hazers; antifoaming agents; ignition improvers; anti rust agents; corrosion inhibitors; anti-wear additives, anti-oxidants (e.g. phenolic compounds and derivatives), coating agents and surface modifiers, metal deactivators, static dissipating agents, ionic and nonionic surfactants, stabilizers, cosmetic colorants and odorants and combination thereof; and, wherein the solid materials are selected from the group consisting of carbon or hydrocarbon solids; coke; graphitic solids; micro-agglomerated asphaltenes, iron rust; oxidative corrosion solids; bulk metal particles; paint particles; surface coating particles; plastic particles or polymeric particles or elastomer particles rubber particles; catalyst fines; ceramic particles; mineral particles; sand; clay; earthen particles; bacteria; biologically generated solids; and combination thereof.
 18. The low sulfur heavy marine fuel composition of claim 15 wherein residual marine fuel oil prior to hydroprocessing and microwave treatment has a sulfur content greater than 1.0 wt. % sulfur.
 19. The composition of claim 15, wherein the heavy marine fuel oil composition is compliant to ISO 8217 (2017) and has a sulfur content (ISO 14596 or ISO 8754) between the range of 0.5% wt. and 0.05% wt.
 20. The composition of claim 15, wherein the heavy marine fuel oil composition is of merchantable quality. 